First I want to say thanks to everyone who posted their solutions for this problem.
I ended up having to take an indoor photo of about 30 people in a confined space (an office). They were in about 4 or 5 rows, so I needed a lot of depth of field.
I stood up on a chair and set my camera to manual exposure, ISO 1600, f6.3 at 1/60th. I was using a Canon 5D Mark 2 with the flash mounted on the camera. First I tried using the Gary Fong (which is supposed to “spread the light”) and that didn’t work. Incredibly, what worked was popping up the little white plastic bounce card on the flash and bouncing the light off the ceiling. The photo came out perfectly exposed and everyone is tack sharp from front to back.
Thanks again for all your ideas!!